1 files changed, 94 insertions, 0 deletions
diff --git a/pkg/v1/remote/layer.go b/pkg/v1/remote/layer.go
new file mode 100644
index 0000000..b2126f5
--- /dev/null
+++ b/pkg/v1/remote/layer.go
@@ -0,0 +1,94 @@
+// Copyright 2019 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package remote
+
+import (
+	"io"
+
+	"github.com/google/go-containerregistry/internal/redact"
+	"github.com/google/go-containerregistry/internal/verify"
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/partial"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+// remoteImagelayer implements partial.CompressedLayer
+type remoteLayer struct {
+	fetcher
+	digest v1.Hash
+}
+
+// Compressed implements partial.CompressedLayer
+func (rl *remoteLayer) Compressed() (io.ReadCloser, error) {
+	// We don't want to log binary layers -- this can break terminals.
+	ctx := redact.NewContext(rl.context, "omitting binary blobs from logs")
+	return rl.fetchBlob(ctx, verify.SizeUnknown, rl.digest)
+}
+
+// Compressed implements partial.CompressedLayer
+func (rl *remoteLayer) Size() (int64, error) {
+	resp, err := rl.headBlob(rl.digest)
+	if err != nil {
+		return -1, err
+	}
+	defer resp.Body.Close()
+	return resp.ContentLength, nil
+}
+
+// Digest implements partial.CompressedLayer
+func (rl *remoteLayer) Digest() (v1.Hash, error) {
+	return rl.digest, nil
+}
+
+// MediaType implements v1.Layer
+func (rl *remoteLayer) MediaType() (types.MediaType, error) {
+	return types.DockerLayer, nil
+}
+
+// See partial.Exists.
+func (rl *remoteLayer) Exists() (bool, error) {
+	return rl.blobExists(rl.digest)
+}
+
+// Layer reads the given blob reference from a registry as a Layer. A blob
+// reference here is just a punned name.Digest where the digest portion is the
+// digest of the blob to be read and the repository portion is the repo where
+// that blob lives.
+func Layer(ref name.Digest, options ...Option) (v1.Layer, error) {
+	o, err := makeOptions(ref.Context(), options...)
+	if err != nil {
+		return nil, err
+	}
+	f, err := makeFetcher(ref, o)
+	if err != nil {
+		return nil, err
+	}
+	h, err := v1.NewHash(ref.Identifier())
+	if err != nil {
+		return nil, err
+	}
+	l, err := partial.CompressedToLayer(&remoteLayer{
+		fetcher: *f,
+		digest:  h,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return &MountableLayer{
+		Layer:     l,
+		Reference: ref,
+	}, nil
+}